JK Rowling's newest play,Watch Fast & Furious 7 Online Harry Potter and the Cursed Child, sold over 175,000 tickets in 24 hours -- but not everyone is equally enthusiastic. 

All across social media, fans of the movie have been criticizing the writer for casting a black actress in the role of Hermione. In an interview with The Observer released today, JK Rowling slammed her critics, call them a "bunch of racists." Noma Dumezweni, playing Hermione, was simply "the best actress for the job."

"With my experience of social media, I thought that idiots were going to idiot," Rowling told The Observer."But what can you say? That’s the way the world is."

Rowling carefully debunked all of her "idiots'" responses. Some of her critics had complained that Hermione must be white because she had "turned white from shock" in one of the series. But Rowling simply used that as an expression, and never meant to imply the character's race.

'I am so proud that I am in it. ’- @MissDumezweni #HarryPotterPlay pic.twitter.com/HNwDrnXwuS

— Pottermore (@pottermore) June 1, 2016

"I had a bunch of racists telling me that because Hermione ‘turned white’ – that is, lost colour from her face after a shock -- that she must be a white woman, that I have a great deal of difficulty with," Rowling told The Observer. "I decided not to get too agitated about it and simply state quite firmly that Hermione can be a black woman with my absolute blessing and enthusiasm."

Canon: brown eyes, frizzy hair and very clever. White skin was never specified. Rowling loves black Hermione 😘 https://t.co/5fKX4InjTH

— J.K. Rowling (@jk_rowling) December 21, 2015

For John Tiffany, the director of The Cursed Child, the casting has proven influential. Despite all the hateful social media backlash, Tiffany thinks the experience will encourage viewers to challenge their assumptions and racial biases. 

"What shocked me was the way people couldn’t visualise a non-white person as the hero of a story," Tiffany told The Observer. "It’s therefore brilliant that this has happened."

Rowling may not have silenced her critics, but at least she spoke up to them.